əˌsēd.əfə̇ˈkāshən, aˌs-, -ˌse- noun
( -s )
Etymology: acet- + -i- + -fication
1. : a turning sour or into vinegar especially through the action of bacteria
2. : the production of acetic acid by acetic fermentation : the growth in an alcoholic medium of bacteria that produce acetic and lactic acids